Workpiece transfer devices

ABSTRACT

This device for transferring workpieces or blanks, notably in a forging press, from one working station to another, in a sequence of working stations comprising for example forging dies, is collapsible and comprises a plurality of clamps adapted to grip the blanks, release them completely from the dies and move same laterally through a distance corresponding to the gap between adjacent dies, and lay the blank into the next die, and eventually resume their initial position. Said clamps are designed to move forwards as their jaws are closed through a toggle mechanism.

States Patent Knierim 1 Mar. 27, 1973 [54] WORKPIECE TRANSFER DEVICESFOREIGN PATENTS OR APPLICATIONS Inventorl Henri Kniel'im,Boulogne'Billan- 729,828 12 1942 Germany .214 1 BB court, France [73]Assignee: Societe Des Aciers Fins De Lest, Primary EXami'1eTGefaldFol'lenla Boulogne-Billancourt (I-Iauts de Assistant Examiner-George F.Abraham Seine), France Attorney.-Richard K. Stevens et al.

[22] Filed: Nov. 29, 1971 [57] ABSTRACT [21] Appl. No.: 202,856

This device for transferring workpieces or blanks, notably in a forgingpress, from one working station to [30] Foreign Applicaflon Prinmy Damanother, in a sequence of working stations comprising Dec. 8, 1970France ..7044l22 for example forging dies, is collapsible and comprisesa plurality of clamps adapted to grip the blanks, [52] US. Cl. ..2l4/lBB release them completely from the dies and move same Cl- ..B23qlaterally through a distance corresponding to the gap [58] Field OfSearch ..214/1 BB, 1 B between adjacent dies, and lay blank into thenext 56 R f d die, and eventually resume their initial position. Said 1e erences Cue clamps are designed to move forwards as their jaws UNITEDSTATES PATENTS are closed through a toggle mechanism.

3,432,042 3/1969 Bautz ..2l4/1 BB 5 Claims, 8 Drawing Figures 4 A1 A2 A3I A4 B2 T3 T3 T5 r2 J 77 F 1 1 H C V E PATENTEUHARZYISYS 3,722,712

SHEET 2 [IF 4 PATEWEDHARZY 1975 SHEET 3 OF 4 B0 DU 00 DD WORKPIECETRANSFER DEVICES The present invention relates to a device fortransferring workpieces or the like between successive treatment ormachining stations, and more particularly to an apparatus fortransferring workpieces or blanks in a forging press of the multiple-dietype, wherein the various dies correspond to successive forgingoperations to be performed on each workpiece r blanks.

The device according to this invention is therefore designed formechanically handling notably blanks between the various dies of aforging press, and also for automatically discharging the cutting burrsand beards.

According to a preferred form of embodiment the transfer deviceaccording to this invention constitutes a separate self-contained unitmounted to a pivoted support whereby it can be retracted to aninoperative position.

This device comprises a plurality of clamps for gripping the blanks,stripping or releasing these blanks completely from their dies, movingsaid blanks laterally by a distance corresponding to the intervalexisting between two adjacent or successive dies, and depositing theblank into the next die and eventually returning the clamps to theirinitial position.

Preferably, the number of clamps will correspond to the number of diesto afford a complete automation of the transfer steps, from the firstdie to the lastone.

The clamps equipping the transfer device according to this invention aretherefore of a particular type wherein the closing movement of the clampjaws is attended by a forward or feed movement of the clamp. Theseclamps are constructed according to the lazytongs or toggle principleaffording a considerable constructional compactness.

The transfer device and the clamp means of this invention will now bedescribed more in detail with reference to the accompanying drawingsillustrating diagrammatically by way of example a typical form ofembodiment of the invention. In the drawings:

FIG. 1 is a plane view from above showing the transfer device assembly;

FIG. 2 is an elevational view of the vertical feed mechanism of thetransfer device;

FIG. 3 is a plane view from above of the transfer device in itsoperative position in relation to the dies;

FIG. 4 is an elevational view showing the pivoted arms supporting thetransfer device;

FIG. 5 illustrates a clamp according to this invention in its openposition;

FIG. 6 illustrates the same clamp in its closed position;

FIG. 7 is a diagrammatic illustration of the clamp, for explaining itsmode of operation, and

FIG. 8 is a more detailed view of the clamp mechanism driving system.

In the specific form of embodiment illustrated the number of clamps,which corresponds to the number of dies, is four, i.e. clamps A,, A Aand A,. These clamps are carried by four adjustable horizontal arms 8,,B B and 8,, respectively (FIG. I) mounted to a carriage C (FIGS. 1 and2) adapted to travel vertically and responsive to a double-actingfluid-operated actuator V (FIG. 2), this carriage being guided duringits travel by a vertical member or slideway E (FIG. 2) comprising ballsockets D (FIG. 2) also mounted to a translation carriage F.

The distance d between the axes of adjacent clamps is selected tocorrespond to the gap between successive dies or die pitch. It will benoted that the overhang mounting of the clamps in the direction of theirmutual alignment in relation to the superposed arms B B and B B isadvantageous in that the carriage can be constructed with overalldimensions smaller than those of the clamps proper.

The translation carriage F (FIG. 1) permits of displacing the clampslaterally, i.e. in their alignment direction. Its stroke is equal to thedie pitch and thus permits of moving clamp A for instance, to theposition previously occupied by clamp A while clamp A takes the previousposition of A and this clamp A assumes the previous position of clamp AThe movements of carriage F are controlled through actuator G (FIGS. 1and 2) and guided by slideways H rigid with a supporting or bed plate P.This plate P which, after a suitable vertical adjustment, is secured andlocked in position by means of studs on the die carrier, is alsoequipped with hydraulic means for controlling and regulating theactuators.

The complete device mounted on said supporting plate P is collapsible tofacilitate the access to the dies. To this end, the device is secured toone end of a pivoted arm L which, in the typical form of embodimentillustrated (FIGS. 3 and 4) consists of two sections pivoted at threepoints. This arm L is secured at its opposite end to the frame structureof the press S. It is shown in thick lines, in FIG. 3, in the operativeposition of the transfer device and in chain-dotted lines in itsretracted position freeing the access to the die.

The hand lever M is provided for adjusting the vertical position of thepivoted arm and therefore the set of clamps in relation to the dies(FIG. 4).

In the form of embodiment illustrated, which is consistent with theconditions required for releasing the clamp carrier assemblycorresponding to the diagram of FIG. 3, the arm comprises three pivotpins K K and K and is comprised of two sections N, and N this lastsection N being bent to provide the maximum free space or clearanceabout the frame structure of the press in the retracted position of thedevice.

The clamps according to this invention, which are used for transferringthe blanks or like workpieces from one die to another, are characterizedin that they are fed forwards as theirjaws are being closed, thussparing a travel of the clamp supporting carriage C.

Clamps having this specific feature are already known, but thoseimplemented in the present invention are advantageous in that theirconstruction is more compact and their gripping or clamping efficiencyis greatly enhanced.

The structure of the clamp according to this invention is illustrateddiagrammatically in FIG. 7, as far as its principle of operation isconcerned, and in FIG. 5, 6 and 8 for its mode of construction.

It comprises a pair of movable jaws M and M pivotally connected at 1 andla to links 10, and at 2 and 2a to links 13, the other ends of theselinks 10, 13 being pivoted at 3, 3a and 4, 4a, respectively, to the arms5 and 5a of a fork shaped support of which the central shank comprises acentral bore 8 constituting the cylinder of a double-acting hydraulicactuator in which a piston 9 is slidably mounted.

Secured to this piston 9 is a rod 11 having its outer end rigid with atrunnion supporting head 7 (FIGS. 7 and 8) to which links 6 have one endpivotally connected, the other ends 12 of these links 6 being pivotallyconnected to other links 10 and 13, respectively.

These clamps operate as follows:

In the inoperative position (illustrated in FIG. the clamp is open, dueto the action of said actuator, the piston 9 thereof being urged to theright (as seen in FIGS. 5, 6 and 7) of cylinder 8.

The double-acting actuator of each clamp is controlled to this end by apair of fluid pipe lines T and T (clamp A), T and T (Clamp A T and T:(clamp A T and T, (clamp A as shown in FIG. 1.

Hydraulic fluid is fed through the aforementioned pipe lines to movepiston 9 to the left (as seen in FIGS. 5, 6 and 7), whereby the trunnionsupporting head 7 is moved back and the links 10 and 13 are caused toform an X, thus combining a forward movement ofjaws M andM with theclosing thereof (FIG. 6) while exerting, due to the specific structureof this toggle mechanism, a very powerful clamping action of said jawson the workpiece disposed therebetween.

The transfer device proper will now be described with reference to FIG.3.

After a billet or other blank has been deposited as a first operation bymeans of a conveyor not comprised in the transfer and forging means, thebillet or blank is slightly lifted by the press ejectors.

Then the operator starts the transfer cycle proper by actuating theclamps. Clamp A, is actuated and grips the blank burr.

After a certain time lag, the clamps are raised by the carriage C drivenby actuator D to permit a complete release of the blank from theimpression of die 0,.

At the end of the lifting step the carriage F controlled by actuator Gis moved laterally through a distance equal to the die pitch, thusmoving the clamp A to the position previously occupied by clamp A andpositioning the blank above the impression of the second die Q At thismoment the carriage C is lowered and the clamps are opened while theyrecede and allow the blank to drop into the impression of the next die QUpon completion of the forging operation and when the transfer devicehas resumed its initial position, the blank is picked up by the nextclamp A of the transfer device which, after another cycle of operation,will drop it into the third die Q At this time, another billet isintroduced at the first station for performing the first operationthereon. This billet, after the forging operation, will be transferredby the clamp A of the transfer device as described hereinabove.

During this same cycle, the clamp A will transfer the blank from thethird clamp to the fourth blank 0,.

A fresh billet is introduced every other cycle: therefore, two blanksare constantly transferred simultaneously.

Similarly, considering the specific case of a forging press, it would bepossible to introduce a billet at each cycle and thus have four blankstransferred during the same operation.

On the other side of the dies a movable bar R operating in synchronismwith the front transfer is provided for supporting the rear end portionsof the blanks of which the insufficient rigidity of the burrs makes ithardly possible to pick up these blanks by means of the front clampsalone. This movable bar is operated by means of suitable hydraulicactuators and performs simultaneous longitudinal and approach movements.The approach movement takes place in a horizontal plane under thecontrol of a parallel-motion system Z (FIG. 3). The other movement takesplace in a vertical plane and is controlled by a similar parallel-motionsystem (not shown) so as to perform the longitudinal feed and the upwardmovement of the movable bar.

These movements are synchronized with the clamping and travel or feedmovements of the clamps. The edges of the workpieces or blanks slidesubsequently along the bar R during the lateral movement.

The workpiece or blank transfer device according to the presentinvention as described hereinabove and illustrated in the attacheddrawing is advantageous, in comparison with hitherto known transfersystems, in that the control means and the number of motions are greatlysimplified, that it is particularly compact due to its retractibility,and that its light weight permits of securing it for example to theframe structure of a press S, thus making is possible to dispense withfloor base plates or like mountings; furthermore, this device isextremely versatile and adjustable, notably through the possibility ofadjusting the clamp supporting arms B and B for adapting the device tomiscellaneous applications.

Of course, various modifications and variations may be brought to thestructure shown and described herein, without departing from the basicprinciples of the invention assetforth in the appended claims.

What is claimed as new is 1. Device for transferring workpieces or thelike between successive working stations, which comprises a series ofaligned clamps mounted on a first carriage movable in a horizontaldirection, the distance between adjacent clamps being constant and equalto the gap between two successive working stations, the complete seriesof clamps being adapted to be moved by means of another carriagesupporting said first carriage and its driving mechanism, said othercarriage being vertically movable, thedevice being characterized in thatthe clamps and carriages constitute a separate unit mounted on one endof a pivoted arm secured to the frame structure of a press whereby saidunit is collapsible to an inoperative position to facilitate the accessto said working stations.

2. Device accordingto claim 1, characterized in that said clamps aremounted on horizontally adjustable arms forming a part of said firstcarriage, and that the pivoted arm aforesaid is associated with meansfor adjusting the vertical position of the pivoted arm, said last-namedmeans being located at the mounting of said pivoted arm on said framestructure.

3. Device, according to claim 2, characterized in that said clampsoverhang the ends of said arms and are. aligned in a directiontransverse to said arms.

4. Device according to claim 1, characterized in that it is used fortransferring workpieces or blanks of relatively moderate rigidity incombination with a movable means of at least one link, whereby theselinks cross each other as an X" in the closed position of said jaws, theclamp assembly further comprising a trunnion-supporting head operativelyconnected in turn through other links to said first-named links, and adoubleacting fluid-operated actuator operatively connected to saidtrunnion-supporting head to move it and thus con trol said links byvarying the angle formed therebetween.

1. Device for transferring workpieces or the like between successiveworking stations, which comprises a series of aligned clamps mounted ona first carriage movable in a horizontal direction, the distance betweenadjacent clamps being constant and equal to the gap between twosuccessive working stations, the complete series of clamps being adaptedto be moved by means of another carriage supporting said first carriageand its driving mechanism, said other carriage being vertically movable,the device being characterized in that the clamps and carriagesconstitute a separate unit mounted on one end of a pivoted arm securedto the frame structure of a press whereby said unit is collapsible to aninoperative position to facilitate the access to said working stations.2. Device according to claim 1, characterized in that said clamps aremounted on horizontally adjustable arms forming a part of said firstcarriage, and that the pivoted arm aforesaid is associated with meansfor adjusting the vertical position of the pivoted arm, said last-namedmeans being located at the mounting of said pivoted arm on said framestructure.
 3. Device according to claim 2, characterized in that saidclamps overhang the ends of said arms and are aligned in a directiontransverse to said arms.
 4. Device according to claim 1, characterizedin that it is used for transferring workpieces or blanks of relativelymoderate rigidity in combination with a movable supporting bar adaptedto act as a bearing member to the ends of said workpieces or blankswhich are opposite to said clamps, means being also provided forsynchronizing the movements of said bar in relation to the clampmovements.
 5. Device according to claim 1, characterized in that saidgripping and tightening clamps comprise on jaws which move forward asthey are closed, mounted on a fork shaped fixed support having twoprojecting arms, the two movable jaws of each clamp being eachoperatively connected to the arm on the opposite side by means of atleast one link, whereby these links cross each other as an ''''X'''' inthe closed position of said jaws, the clamp assembly further comprisinga trunnion-supporting head operatively connected in turn through otherlinks to said first-named links, and a double-acting fluid-operatedactuator operatively connected to said trunnion-supporting head to moveit and thus control said links by varying the angle formed therebetween.